I've always loved the idea of a wedding on a boat, mostly due to my love of The Little Mermaid as a kid. Tiana's wedding is a close second though.

I love Mulan's wedding dress but this wedding can't be my favorite because Mulan and Shang are my least favorite.

Ariel's as well.

Ariel's wedding because the scene was so joyful and endearing. You get to see Ariel and Eric kiss (and not worry about Ursula trying to tear them apart) and her family was there, too with approval. There was also a hug between Ariel and Triton which confirmed that they still love each other and are still family.
And, Sebastian got his revenge on Chef Louis, tee hee hee!

Other favorite wedding scenes were Cinderella 1 and 3, and Rapunzel's wedding.

Cinderella's wedding was beautiful because we get to see her finally achieve her happy ending after everything that she went through-especially with putting up with her horrible stepfamily. In the third movie, not only did she get a husband, but also Anastasia finally became her real sister.

Rapunzel's wedding was a fun treat! I like how Eugene went "Wow!" when he saw her coming down on the aisle. And their kiss was really cute! (I just hope that the messy reception hall didn't ruin the rest of their wedding thanks to Maximus and Pascal).